JP3325856B2 - L2 integrated access method - Google Patents

Abstract

An L2 integrated access (L2IA) system is contructed from: L2IA subscribers for supporting communications between user terminals using various communication media, each L2IA subscriber having an L2IA identifier for uniquely identifying each L2IA subscriber within the L2 integrated access system and a terminal ID for uniquely identifying each L2IA subscriber within each communication medium associated with each L2IA subscriber; and an L2IA relay network formed by relay units to be connected with the L2IA subscribers through various communication media and relaying communications between the L2IA subscribers through the L2IA relay network, each relay unit being provided in correspondence to one communication medium such that at least one relay unit is provided in correspondence to each communication medium, and each relay unit having an L2IA relay ID for uniquely identifying each relay unit within the L2IA relay network and a terminal ID for uniquely identifying each relay unit within each communication medium associated with each relay unit, and an LPR (Location and Preference Register) for registering an RLD (Registered Location Data) indicating a terminal ID of an L2IA subscriber and an L2IA relay ID of a relay unit for each potentially available communication medium in correspondence to the L2IA identifier of each L2IA subscriber, such that the relay unit relays the communications between the L2IA subscribers according to the RLDs registered in correspondence to the L2IA identifies of the L2IA subscribers. <IMAGE>

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a PPP (Point-to-Point).
-Point Protocol) A data link (Layer 2) that provides a multifunction access to a computer network by providing a communication line for transmitting packets and PPP-related information (such as a login prompt and a password prompt) without depending on a physical line. ) Regarding the integrated access method.

[0002]

2. Description of the Related Art At present, as a method of accessing a computer network such as the Internet or an intranet from a mobile terminal, a method of dialing up through a public network and connecting to a PPP access server is generally used.
However, according to the conventional method, when it is necessary to change the communication medium due to movement of a mobile terminal during a certain communication session, the communication medium cannot be changed while maintaining the communication session, or the communication medium is changed. Therefore, there is a problem that it is necessary to rewrite the program code for changing the API level.

[0003] Technologies for securing the freedom of users to move geographically and for eliminating the dependence on communication media include Mobi.
le IP, CDPD (Cellular Digital Packet Dat
There are various proposals such as a), L2-1 call (Seamless Network), one number service, and Virtual LAN.

Mobile IP uses two types of global IP addresses to identify the terminal itself on the home network and to identify the position of the terminal registered in the home agent installed on the home network.
The mobility of the mobile terminal is ensured by updating the IP address for identifying the position of the terminal at the destination registered by the home agent each time the terminal moves. To receive a packet addressed to itself at the destination when the terminal moves, the home agent receives the packet once and sends it to the IP address of the mobile terminal managed by the home agent by IP tunneling.
Although the mobility of the terminal is ensured to enable media exchange during communication, there are problems that it can be used only for communication using IP and that the IP protocol stack needs to be changed.

[0005] In CDPD, a global IP address is used to identify a terminal. In the CDPD network, the MD-IS (Mobile
Data Intermediate System) is called Home MD-IS, and the MD-IS connected to the moving network
Called erving MD-IS. When the terminal moves, the terminal becomes Servin
g Serving M is connected to the MD-IS network.
Notify the D-IS and request the Serving MD-IS to issue a location registration request to the Home MD-IS. Serving MD-
Upon receiving the request from the IS, the Home MD-IS of the terminal maps the Serving MD-IS that manages the network to which the terminal is currently connected to the terminal as location registration of the terminal. The packet addressed to the terminal always arrives at the Home MD-IS first, and is then forwarded to the Serving MD-IS based on the registered location registration. When this packet is received, Serving MD-IS forwards the packet to the terminal, so that the terminal can receive the packet wherever it moves. CLN between MD-IS
Since communication is performed using the P (Connectionless Network Protocol), CDPD has scalability for the movement of terminals, and since communication is performed through a dedicated network for CDPD, security is higher in terms of security than through an open IP network such as the Internet. The nature is also high.

However, in the CDPD network, only the mobility of the terminal is secured, and the medium used during communication cannot be exchanged. In order to perform a dial-out service from the server side, it is necessary to statically assign a global IP address. Especially private IP
Because the dial-out service from the server on the intranet that uses the address requires conversion from a private address to a global address, CDP
It is difficult to realize in D. In addition, CDP
The media that can use the D network are also limited, and it is difficult to support new media.

[0007] L2-1 call system (Seamless Network)
In this document, networks of different media are connected to each other so as to recognize telephone numbers of different media as a function of the network, thereby enabling communication between terminals belonging to different media. Telephone numbers are used to identify terminals, and various types of communication are used, not limited to IP. However, in order to support new media, it is necessary to incorporate a system capable of recognizing a telephone number, which is an identifier of a terminal in the new media, into the network. A service for sending a packet to a user terminal by making a call) or exchanging media during communication is not considered.

[0008] In addition, L2TP provides access to a sophisticated network using PPP tunneling technology, but L2TP cannot exchange media during communication.
A dial-out service is also considered, but dial-out connection to most users is not possible.

The one-number service is a service for receiving an incoming call at the center once and connecting to the media registered by the user in advance at the center, and a telephone number is used to identify the user. In this service, since the allocated number indicates the geographical condition and the center to which it is connected is fixed, the call path may be wasted. For example, there is a case where a call is made from Osaka to a center in Tokyo and a call is made from a center in Tokyo to a call in Osaka. In this service, the media used during communication cannot be exchanged.

[0010] In the Virtual LAN, a terminal sends an identifier given to the terminal depending on a network protocol to be used, for example, an IP address, to a server which manages the position of the terminal. The terminal obtains the identifier and establishes a communication path directly with the terminal. In this method, the mobility of the terminal is secured, but the access medium used during communication cannot be exchanged. In addition, since the terminal attempts to connect directly to the other party, a communication path cannot be established if the communication media networks are not connected, and it is difficult to deal with new media.

[0011]

As described above, conventionally, when a user connects to a computer network such as the Internet or an intranet, dial-up connection using a telephone line at home or from a company network is required. Was the majority. However, the development of wireless communication media represented by mobile phones and PHS has been remarkable, and the use of access by dial-up connection using these media has become widespread. In addition, the number of users who use notebook computers has increased, and securing mobility of terminals has become an important issue.

At present, when changing the communication medium used during communication, it is necessary to temporarily terminate the communication session of the communication application used on the computer, change the communication medium, and then establish the communication session again. There is.

[0013] For example, if the server is connected to the server using the PHS and ftp is performed, it is difficult to change the media used for communication from the PHS to the mobile phone without ending the ftp session and continue the ftp. It is.

When attempting to connect to the majority of users from the server, if communication is performed using IP, it is necessary to assign static IP addresses by the number of dial-out connection destination users. . Given the lack of IP addresses, it is very difficult to provide scalability for dial-out connections. In addition, it is necessary to prepare a large number of communication interfaces used for dial-out.

When a user accesses a network, the user himself can use a modem, a mobile phone adapter, a LAN, or the like.
It is necessary to prepare a communication device for the media to be used, such as a card (Ethernet), and it is necessary for the side managing the network to use the communication device for each media. This not only limits the communication media available to the user, but also necessitates the provision of a communication device for the new media as it communicates with each new media, making it difficult to respond to the new media. It means that

Accordingly, the present invention provides a communication link for transmitting a PPP packet and PPP-related information without depending on a physical link, thereby realizing multi-function access to a computer network. Layer 2) It aims to provide an integrated access method.

[0017]

Therefore, in the present invention,
An L2IA (Layer 2 unified access) subscriber supporting communication between user terminals using various communication media, wherein each L2IA subscriber uniquely identifies an L2IA subscriber in the system.
An IA identifier, a terminal ID for uniquely identifying each L2IA subscriber in each communication medium associated with each L2IA subscriber, a plurality of relay units, and at least one LPR (Location and Preference).
L2IA relay network, which is connected to an L2IA subscriber via various communication media, and is connected to an L2IA relay network via the L2IA relay network.
The relay unit relays communication between subscribers. Each relay unit is provided corresponding to one communication medium, and is an L2I for uniquely identifying each relay unit in the L2IA relay network.
A relay ID and a terminal ID for uniquely identifying each relay unit within each communication medium associated with each relay unit, wherein the LPR is an L2IA subscriber for each potentially available communication medium. Terminal ID of
RLD (Re) that indicates the L2IA relay ID of the relay unit in association with the L2IA identifier of each L2IA subscriber
gistered location data), and the relay unit relays communication between the L2IA subscribers based on the registered RLD in association with the L2IA identifier of the L2IA subscriber. Provide system.

In the present invention, the L2IA subscriber includes at least one communication interface, an e-type L2IA subscriber having one PPP interface and one L2IA interface, at least one communication interface, and at least one PPP interface. , Including an N-type L2IA subscriber having one L2IA interface, wherein each communication interface can set up a connection with a relay unit,
Each PPP (Point-to-Point Protocol) interface can exchange a PPP packet and PPP-related information with a user terminal, and each L2IA interface can selectively interface a communication interface and a PPP interface. I do.

In the present invention, each L2IA subscriber has a function of establishing one or more L2IA-U-Planes, which are logical connections through which user communication data flows, to one or more other L2IA subscribers. It is characterized by having.

Further, in the present invention, each relay unit is
A function of transmitting / receiving a signaling message to / from another relay unit in the 2IA relay network and the LPR;
A function of establishing an L2IA channel, which is a logical connection that supports L2 integrated access from the subscriber to the relay unit, to the L2IA subscriber.

In the present invention, the R registered in the LPR
The LD is further characterized by indicating the priority of each potentially available communication medium set by the user and, optionally, the current availability of each potentially available communication medium.

Also, in the present invention, a certain L2IA subscriber provided in a certain user terminal associated with a certain communication medium is dial-up connected to another L2IA subscriber provided in a user's home network associated with another communication medium. A connection to a certain relay unit provided corresponding to the certain communication medium suitable for the certain L2IA subscriber, and specifying the L2IA identifier of the other L2IA subscriber for the certain relay unit. By doing so, the other L2
LP corresponding to L2IA identifier of IA subscriber
Based on a certain RLD registered by R, the certain relay unit sets a connection to another relay unit provided corresponding to the other communication medium suitable for the other L2IA subscriber, and the certain RLD On the basis of the,
The other relay unit sets a connection to the other L2IA subscriber.

Further, according to the present invention, a certain L provided in a home network of a user accompanying a certain communication medium is provided.
2IA subscriber, dial-out connection to another L2IA subscriber provided in a certain user terminal associated with another communication medium, a relay unit provided corresponding to the certain communication medium suitable for the certain L2IA subscriber To the other L2IA subscriber by specifying the L2IA identifier of the other L2IA subscriber for the certain relay unit.
LP corresponding to L2IA identifier of IA subscriber
Based on a certain RLD registered by R, the certain relay unit sets a connection to another relay unit provided corresponding to the other communication medium suitable for the other L2IA subscriber, and the certain RLD On the basis of the,
The other relay unit sets a connection to the other L2IA subscriber.

Further, according to the present invention, a certain L2IA subscriber provided in a user terminal, which is communicating with another L2IA subscriber provided in a user's home network, uses a communication medium used for communication with the other L2IA subscriber. Requesting a handover to a first relay unit provided corresponding to the first communication medium and changing the handover from the first communication medium to the second communication medium, and suitable for the certain L2IA subscriber. By setting a connection to a second relay unit provided corresponding to the second communication medium, and specifying the L2IA identifier of the other L2IA subscriber for the second relay unit. , The other L
L corresponding to the L2IA identifier of the 2IA subscriber
Based on a certain RLD registered by the PR, the second relay unit connects to a third relay unit provided corresponding to a communication medium associated with a home network of a user suitable for the other L2IA subscriber. And the first relay unit disconnects the connection between the certain L2IA subscriber and the first relay unit and the connection between the first relay unit and the third relay unit. It is characterized by.

Further, according to the present invention, a certain L2IA subscriber provided in a user terminal, which is communicating with another L2IA subscriber provided in a user's home network, is used for communication with another L2IA subscriber. By changing the first communication medium from the first communication medium to the second communication medium by requesting the first relay unit provided for the first communication medium to perform the handover, One relay unit is the L2IA of the certain L2IA subscriber
An RLD registered by the LPR in association with the identifier
Requesting and setting the second relay unit provided corresponding to the second communication medium suitable for the certain L2IA subscriber and setting the connection to the certain L2IA subscriber to the second relay unit indicated by the certain RLD. The first relay unit sets a connection to the second relay unit so that communication data flows from the first relay unit to the certain L2IA subscriber via the second relay unit, The first relay unit notifies the second relay unit to a third relay unit provided corresponding to a communication medium associated with a user's home network suitable for the other L2IA subscriber, and notifies the third relay unit of the third relay unit. Relay unit sets a connection between the third relay unit and the second relay unit and Starting transmission of communication data and stopping transmission of communication data to the first relay unit, wherein the first relay unit establishes a connection between the certain L2IA subscriber and the first relay unit; The connection between the first relay unit and the second relay unit and the connection between the first relay unit and the third relay unit are disconnected.

Further, according to the present invention, when a certain L2IA subscriber provided in a user's home network interrupts communication with another L2IA subscriber provided in a user terminal, a communication state of the communication with the other L2IA subscriber is interrupted. And when the other L2IA subscriber reconnects to the certain L2IA subscriber, the communication with the other L2IA subscriber is restarted from the stored communication state.

Further, according to the present invention, in the above-mentioned L2 integrated access system, an L2IA subscriber provided at a certain user terminal associated with a certain communication medium is provided in a home network of a user associated with another communication medium. A method for dial-up connection to another L2IA subscriber, comprising:
Setting up a connection from the IA subscriber to a certain relay unit provided corresponding to the certain communication medium suitable for the certain L2IA subscriber;
(B) the L2IA of the other L2IA subscriber from the certain L2IA subscriber to the certain relay unit;
(C) specifying the L of the other L2IA subscriber specified in step (b).
2 based on a certain RLD registered by the LPR in association with the second IA identifier,
Setting a connection to another relay unit provided corresponding to the other communication medium suitable for the IA subscriber; and (d) setting the other L2IA from the other relay unit based on the certain RLD. Setting up a connection to a subscriber.

Further, according to the present invention, in the above-mentioned L2 integrated access system, a certain L2IA provided in a user's home network associated with a certain communication medium.
A dial-out connection method from a subscriber to another L2IA subscriber provided in a certain user terminal attached to another communication medium, comprising:
Setting up a connection from the IA subscriber to a certain relay unit provided corresponding to the certain communication medium suitable for the certain L2IA subscriber;
(B) the L2IA of the other L2IA subscriber from the certain L2IA subscriber to the certain relay unit;
(C) specifying the L of the other L2IA subscriber specified in step (b).
2 based on a certain RLD registered by the LPR in association with the second IA identifier,
Setting a connection to another relay unit provided corresponding to the other communication medium suitable for the IA subscriber; and (d) setting the other L2IA from the other relay unit based on the certain RLD. Setting up a connection to a subscriber.

Further, according to the present invention, in the above-described L2 integrated access system, the communication with another L2IA subscriber provided in the user's home network is performed.
A handover method in which a certain L2IA subscriber provided in a user terminal changes a communication medium used for communication with another L2IA subscriber from a first communication medium to a second communication medium, wherein (a)
Requesting a handover from the certain L2IA subscriber to a first relay unit provided corresponding to the first communication medium; (b) the certain L2I subscriber
Setting a connection from the A subscriber to a second relay unit provided corresponding to the second communication medium suitable for the certain L2IA subscriber; and (c) setting the second relay from the certain L2IA subscriber to the second relay unit. Specifying the L2IA identifier of the other L2IA subscriber for the unit; and (d) registering the L2IA identifier of the other L2IA subscriber registered by the LPR in association with the L2IA identifier of the other L2IA subscriber specified in step (c). Setting a connection from the second relay unit to a third relay unit provided corresponding to a communication medium associated with a user's home network suitable for the other L2IA subscriber, based on the (e) ) A connection between the certain L2IA subscriber and the first relay unit; To provide a handover method characterized by a step of cutting the connection between the action and said first relay unit and said third relay unit.

Further, according to the present invention, in the above-described L2 integrated access system, another L2IA subscriber provided in a user terminal, which is communicating with another L2IA subscriber provided in a user's home network, uses the other L2IA subscriber. A handover method for changing a communication medium used for communication with a subscriber from a first communication medium to a second communication medium,
(A) requesting a handover from the certain L2IA subscriber to a first relay unit provided corresponding to the first communication medium; and (b) the certain L2IA subscriber in the first relay unit. Acquiring a certain RLD registered by the LPR in association with the L2IA identifier of the L2IA;
Requesting and setting, from the first relay unit, a connection from the second relay unit indicated by the RLD to the certain L2IA subscriber provided corresponding to the second communication medium suitable for the A subscriber; (D) setting a connection from the first relay unit to the second relay unit, and communication data flowing from the first relay unit to the certain L2IA subscriber via the second relay unit (E) from the first relay unit to the other L2IA.
Notifying the second relay unit to a third relay unit provided corresponding to the communication medium attached to the user's home network suitable for the subscriber,
(F) setting a connection from the third relay unit to the third relay unit and the second relay unit to start transmitting communication data to the second relay unit, and Stopping transmission of communication data to the relay unit; (g) a connection between the certain L2IA subscriber and the first relay unit; a connection between the first relay unit and the second relay unit; Disconnecting the connection between the first relay unit and the third relay unit.

Further, according to the present invention, there is provided a reconnection method in the above-mentioned L2 integrated access system, wherein (a) in a certain L2IA subscriber provided in a user's home network, another L2IA subscriber provided in a user terminal is provided.
When the 2IA subscriber interrupts the communication, the other L
Storing the communication state of communication with the 2IA subscriber; and (b) when the other L2IA subscriber reconnects to the certain L2IA subscriber, the communication state stored in the step (a) is changed to the certain state. L2
Resuming communication between the IA subscriber and the other L2IA subscriber.

[0032]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a layer 2 (L2) integrated access system according to the present invention will be described below in detail with reference to FIGS.

<Overall Configuration> FIG. 1 shows the overall configuration of an L2 integrated access system according to this embodiment. This system comprises a B unit 110 and an LPR (Location and Prefeature).
Lnce IA (L2
Integrated Access) relay network 100 and an L2IA subscriber including an e unit 10 and an N unit 20 connectable to the B unit 110 via various communication media 200. Here, the e unit 10 is connected to a user terminal (not shown).

The communication medium 200 is, for example, a C-plan
e and a public telephone network having a U-plane. Cp
The lane is a part for exchanging information between the control part of the communication medium and the terminal to realize call setting / release, various notifications, and the like. U-plane is a portion where actual user data such as voice flows. As will be described later, each communication medium 200 uses a terminal identifier, such as a telephone number, for uniquely identifying the corresponding L2IA subscriber or B unit in each communication medium.

As shown in FIG. 1, the e unit 10 and the N unit 20 are connected to the B unit 110 via various communication media 200. In the L2 integrated access method, an L2IA line is established in the U-plane of the communication medium 200. L2IA line is one C-plane
(L2IA-C-plane) and one or more U-pla
ne (L2IA-U-plane). L
2IA-C-plane is a control channel of the L2IA line, and is used for L2IA such as outgoing / incoming calls and communication suspension / resumption control.
A signaling message for implementing various functions of the integrated access method is transmitted. L2IA-U-plane
Is one of the users' PPP (Point-to-Point Protocol)
A packet consisting of a packet and related information is transmitted.

The L2 integrated access system of the present invention provides the L2IA subscribers, that is, the e-unit 10 and the N-unit 20 in the communication network of FIG.
Various functions are realized by dynamically setting and changing the U-plane.

Next, the L2IA subscriber, the LPR 120, and the B unit 1 constituting the communication network of FIG.
10 will be described in detail.

<L2IA (L2 Integrated Access) Subscriber> The L2IA subscriber is a device used by a user to use the service of the L2 integrated access system. Basically, the user uses this unit to configure the B unit 110 that configures the L2IA relay network 100.
To various media directly. There are two types of L2IA subscribers, e-units 10 and N-units 20. The e-unit 10 is a device used for each moving user, and the N-unit 20 corresponds to an access server located on the user's home network. And can be accessed from a plurality of e units.

As shown in FIG. 2, the e unit 10 includes a plurality of communication interfaces 1 such as an interface card corresponding to a communication medium for connecting to the B unit 110.
1 and the PP of the user flowing through the L2IA-U-plane
It has a PPP interface 12 that can exchange P packets with a user terminal, and an L2IA interface 13 that connects the communication interface 11 and the PPP interface 12 irrespective of the connection format. Alternatively, the e unit 10 may be configured such that the PPP interface 12 and the L2IA interface 13 are connected via the serial interface 14, as shown in FIG.

In practice, the e-unit 10 is a PCMCIA (Personal Computer Memory Card In) on which software for realizing the functions of the e-unit 10 is installed.
ternational Association) card. PCMCIA cards that are generally used include modems, network adapters such as Ethernet and token ring, and flash memories.
The CIA card has a wireless LAN adapter or SCSI
There are also adapters and the like.

This e unit 10 is a designated L2
L2IA-U-plane with IA subscriber
Is a device that can establish When using the L2IA unified access scheme, each user installs the e-unit 10 on his / her user terminal to establish the L2IA-U-plane. Since the e unit 10 has a plurality of communication interfaces corresponding to communication media, it can be directly connected to the B unit 110 via the communication media. The e-unit 10 is a communication medium U-
An L2IA line having only one L2IA-U-plane in the plane is established.

On the other hand, as shown in FIG.
Is a communication interface 2 such as an interface card corresponding to a communication medium for connecting to the B unit 110.
1 and the PP of the user flowing through the L2IA-U-plane
A plurality of PPP interfaces 22 capable of exchanging P packets with a plurality of user terminals;
And an L2IA interface 23 for connecting them regardless of the connection format of the PPP interface 22.

In practice, the N unit 20 is an access router (supporting one or more protocols and relaying data via one or more networks) equipped with software for realizing the functions of the N unit 20. Device).

The N unit 20 is an apparatus capable of establishing an L2IA-U-plane with a plurality of L2IA subscribers. The N unit 20 is provided in the home network of the user of the e unit, and is connected to the B unit 110 via, for example, a dedicated line. The N unit 20 has a communication interface corresponding to a communication medium for directly connecting to the B unit 110. The N unit 20 terminates the PPP connection from the terminal of the user using the L2 integrated access method. N unit 20 is B
U-pl of communication media connected to unit 110
one L2IA-C-plane and multiple L2s
An L2IA line having an IA-U-plane can be established.

Each L2IA subscriber has an identifier called an L2IA identifier uniquely defined in the L2 integrated access system. This L2IA identifier is, for example, 164 format, which will be described later.

In this embodiment, the L2IA subscriber has the following functions.

(1) Transmission / reception control function: A function of performing transmission / reception control for each communication medium for the B unit constituting the L2IA relay network.

(2) Connection request function: For the B unit constituting the L2IA relay network, the L2IA identifier indicating the L2IA subscriber to be connected is checked from its own correspondence table or the like, and this L2IA identifier is transmitted to the B unit. By sending, L2 to specified L2IA subscriber
Function to request establishment of IA-U-plane.

(3) L2IA line establishment / change / disconnection function: An L2IA line is established or used with a B unit directly connected by a communication medium.
A function to establish and change planes dynamically.

(4) RLD (Registered Location Dat)
a) Change request function: Among RLDs, which describe which terminal unit can be connected to which B unit from the LPR as described later, the RLD related to its own L2IA identifier
Function to request change of LD.

(5) Session information storage function: In order to restore the communication state of the L2IA subscriber who has requested the reconnection, the L2IA-U-plane can be uniquely identified. Function to keep communication status. This function can also be used to search for information using the L2IA identifier as a key when communication is resumed.

(6) L2IA-U-plane identification function: a plurality of L2IA multiplexed on one L2IA line
To identify the IA-U-plane, the L2IA-U
-A function of identifying the L2IA-U-plane by assigning the L2IA identifier of the L2IA subscriber on the opposite side of the plane to each L2IA-U-plane or assigning a unique identification number to each L2IA-U-plane. .

(7) Authentication function: other L2 as communication partner
The ability to authenticate IA subscribers.

(8) Network authentication function: A function for authenticating the B units constituting the L2IA relay network.

<LPR (Location and Preference Regi)
ster)> To communicate, each L2IA subscriber has a media-dependent identifier called a terminal identifier that can uniquely identify the L2IA subscriber in each communication medium, such as a telephone number assigned in each communication medium. . This terminal identifier changes when the L2IA subscriber moves to a different communication medium. Each L2IA subscriber may have one or more terminal identifiers corresponding to the communication medium used.

Further, as the L2IA subscriber moves, the position of the appropriate (closest, fastest, cheapest, or randomly selected) B unit connected to the L2IA subscriber, that is, the L2IA indicating the appropriate B unit The relay identifier changes. In addition, the user arbitrarily sets the priority for the communication media to be used.
Whether or not available communication media can be changed depends on the state of the line.

As shown in FIG. 5, the LPR 120 stores these four types of dynamically changing data, ie, a terminal identifier, L
2IA relay identifier, priority, availability of communication media (alive flag) (however, availability of media is optional), and a data unit called RLD (Registered Location Data) having data indicating the corresponding communication media as elements Is an L2IA subscriber's device that manages, as a key, an L2IA identifier that is invariable in the L2 integrated access system and that can uniquely identify the L2IA subscriber.

If the L2IA subscriber has more than one potentially available communication medium, the LPR1
20 manages the RLD by the number of potentially available communication media in association with the L2IA identifier of the L2IA subscriber. L of a certain L2IA subscriber
In each RLD of each potentially available communication medium provided corresponding to the 2IA identifier, the terminal identifier indicates the media dependent identifier of the L2IA subscriber within the communication medium, and the L2IA relay identifier indicates the L2IA relay identifier in the communication medium. Indicates the appropriate B unit provided correspondingly, indicates the priority of the communication medium among the potentially available communication media set by the user, and indicates whether the communication medium is available or not. Indicates whether the media is currently available.

Further, the LPR 120 is interconnected with another B unit or another LPR to thereby form the L2IA relay network 1
00 can be configured. This L2IA relay network 10
0 indicates that each B unit 11 in the L2IA relay network 100
0 or an L2IA relay identifier capable of uniquely identifying the LPR 120 is used.

As shown in FIG. 6, the LPR 120 has a communication interface 121 through which it communicates with the B units and other LPRs constituting the L2IA relay network 100 to exchange information necessary for the signaling operation. L
The PR 120 further has a controller (CTL) 122 for controlling the operation of the LPR 120 and a memory 123 for storing the RLD. Further, the LPR 120 updates the registered information based on a request from the L2IA subscriber or the B unit, and always maintains the latest information.

In practice, the LPR 120 is provided as a device for maintaining and managing a database such as a personal computer or a workstation.

In this embodiment, it is assumed that the LPR 120 has the following functions.

(1) Authentication function: authenticates an L2IA identifier authentication request from a B unit constituting an L2IA relay network, returns the authentication result to the B unit, and authenticates the B unit itself. function.

(2) MARLD (Most Appropriate R)
LD) Sending function: Using the L2IA identifier sent from the B unit constituting the L2IA relay network as a search key, the RLD with the highest priority among the RLDs related to the destination L2IA identifier (this is called MARLD) Is returned to the requesting B unit.

(3) Location registration function: A function for changing each data field of the RLD relating to each L2IA identifier based on a request from an L2IA subscriber or a B unit.

<B Unit> The B unit 110 is a L2
It has an L2IA relay identifier that uniquely identifies itself in the IA relay network 100, and establishes a relay network U-plane with another B unit in the L2IA relay network 100. This relay network U-plane relays the L2IA-U-plane, and the relay network C-plane exchanges signaling messages with other B units and LPR. Also,
The B unit 110 is a device that establishes an L2IA line with an L2IA subscriber. Each B unit is provided corresponding to a specific communication medium, and has a terminal identifier that uniquely identifies the B unit within the specific communication medium. In addition, 2 corresponding to a specific communication medium
One or more B units may be provided.

As shown in FIG. 7, the B unit 110
For example, it has a communication interface 111 corresponding to a communication medium such as an interface card for directly transmitting / receiving an L2IA subscriber used by a user. The B unit 110 further has a controller (CTL) 112 for controlling the operation of the B unit 110 and a communication interface 113 such as an IP network interface for communicating with the B unit and the LPR.

In practice, the B unit 110 can be provided as an access router on which software for realizing the function of the B unit 110 is installed.

In this embodiment, it is assumed that the B unit 110 has the following functions.

(1) Call control function: L2IA of user
A function to control outgoing / incoming calls for each communication medium for subscribers.

(2) Location inquiry function: MA relating to the L2IA identifier of another L2IA subscriber that is the communication partner specified by the connected L2IA subscriber
Function to inquire RLD 120 about RLD. At this time, an inquiry is made by sending a pair of a source and destination L2IA identifier or an L2IA identifier used as a search key.

(3) RLD change request function A function for requesting change of RLD information relating to the L2IA identifier specified in the LPR 120.

(4) Establishment / disconnection of the relay network U-plane
Modification function: relay network C-
Relay network U-plane by plane signaling
And a function of dynamically changing the relay network U-plane in response to a request from the L2IA subscriber.

(5) Handover data storage function: L2
Upon receiving a handover request from an IA subscriber,
Function to save data called handover data (HD). Here, the handover data HD is an identifier for uniquely identifying each handover in the requested B unit,
L2IA relay identifier of the requested B unit, information indicating a pair of L2IA subscribers performing communication,
The data is information indicating that handover is being performed.

<Overall Functions> With the configuration described above, the L2IA system of the present embodiment realizes the following overall functions.

(1) Dial-up connection function: The e unit selects a communication medium, transmits connection information to an appropriate B unit (Be unit) by the transmission / reception control function, and connects. After the connection, the e unit sends the Be unit its L2IA identifier (source L2IA identifier) and the L2IA identifier of the L2IA subscriber to be connected to (the destination L2IA identifier), and the Be unit sends the source and destination L2IA identifiers. Pair or destination L2IA
The identifier is sent to the LPR, and the RLD relating to the destination L2IA identifier is queried from the LPR to obtain it. The Be unit that obtained the RLD is the B unit (BN
L2IA with destination L2IA identifier for unit)
Requests a call to the subscriber's terminal identifier, B
e unit or LPR sets source L2IA identifier to B
Notify N units.

Next, the BN unit makes a call and connects to the terminal identifier specified by the call control function,
Send the source L2IA identifier to N units. The N unit issues a connection permission based on the transmitted source L2IA identifier, and when the connection permission is issued, the BN unit establishes an L2IA-U-plane with the N unit, and connects the e unit to the Be unit. Notify permission. The notified Be unit communicates with the BN unit via the relay U-pla.
ne, the e unit is notified of connection permission, and an L2IA-U-plane is established with the e unit.

With this dial-up connection function, L2
No matter which communication medium the IA subscriber is using or moving to, the designated L2IA
An L2IA-U-plane can be established with the subscriber.

(2) Dial-out connection function: N unit has its own L2IA identifier (source L2IA identifier)
And the L2IA identifier (destination L2IA identifier) of the L2IA subscriber to be connected to is transmitted to the connected B unit (BN unit). If N units are currently BN
If it is not connected to the unit, the transmission / reception control function transmits and connects to the terminal identifier of the BN unit.
Then, the BN unit sends the pair of the source and destination L2IA identifiers or the destination L2IA identifier to the LPR, and queries the LPR for the currently available and highest priority RLD for the destination L2IA identifier. . The BN unit that has obtained the RLD requests the B unit (Be unit) indicated in the RLD to transmit to the terminal identifier of the L2IA subscriber, and
Unit or LPR sends source L2IA identifier to Be
Notify the unit.

Next, the Be unit attempts transmission and connection to the terminal identifier by the transmission / reception control function, and if the connection is not established, notifies the BN unit of the fact,
The LPR is notified that the N units could not be connected. The LPR that has received this notification changes the communication media availability of the corresponding RLD and returns a new RLD that is currently available and has the highest priority after the change to the BN unit. The BN unit that has received the new RLD requests the corresponding B unit (Be unit) to transmit, as described above.

After connecting to the e unit, the Be unit sends the source L2IA identifier to the e unit, and the e unit determines connection permission based on the source L2IA identifier, and notifies the Be unit of the connection permission. B who received this connection permission
The e unit has L2IA-U-pl between the e unit and the e unit.
ane is established, and the BN unit is notified of connection permission.
The BN unit that has received the notification establishes a relay U-plane with the Be unit, notifies the N unit of connection permission, and communicates with the N unit using the L2IA-U-pla.
ne is established.

With this dial-out connection function, L2
Regardless of which communication medium the IA subscriber moves to, the server (N unit) sends L to the e unit.
2IA-U-plane can be established, and the connection with the terminal is a communication medium that reflects the priority set by the user of the terminal.

(3) Handover function Scenario I: e
When the unit is connected to the B unit (B1 unit) using the communication medium and connected to the N unit via the B unit (BN unit) for communication, the e unit issues a handover request to the B1 unit. Then, it connects to another B unit (B2 unit) using another communication medium in the same procedure as dial-up connection, and specifies the L2IA identifier of the N unit to be connected to the B2 unit. Upon receiving this request, the B2 unit requests and obtains the RLD for the L2IA identifier of the N unit from the LPR and obtains a new relay U-plane to the BN unit.
To establish. Then, the e unit establishes an L2IA-U-plane with the B2 unit, and changes the L2IA-U-plane through which the user data flows from the one via the B1 unit to the one via the B2 unit.

With this handover function, communication media can be changed without interrupting user communication.

(4) Handover function Scenario II:
When the e unit is connected to the B unit (B1 unit) using the communication medium and is connected to the N unit via the B unit (BN unit) for communication, the e unit sends a handover request to the B1 unit. The B1 unit requests and obtains a MARLD from the LPR using the L2IA identifier of the e unit as a key. The B1 unit also performs L2IA-U-plane handover.
The handover data HD for distinguishing
The ARLD, the L2IA identifier of the e unit, and the handover data HD are transferred to another B unit (B
2 units).

Next, the B2 unit performs transmission and connection to the terminal identifier indicated in the MARLD. If the connection has failed, the B2 unit notifies the B1 unit of the fact, and the B1 unit receiving the notification requests the LPR to change the RLD and a new MARLD after the change to obtain a new MARLD. After that, the B2 unit tries to connect to the e unit again.

If the connection is successful, the B2 unit establishes an L2IA-U-plane with the e unit, and notifies the B1 unit that the connection has been established. Then, the B1 unit is connected to the B2 unit by the relay Up-p.
establishes the L2IA-U-plane of the user
Is the L2IA-U-pl between the B2 unit and the e unit.
The communication is changed to the communication using ane, and the handover data HD and the L2IA relay identifier of the B2 unit are notified to the BN unit. The BN unit that has received the notification,
A relay U-plane for relaying the L2IA-U-plane identified by the handover data HD is established between the two units, and after the establishment, the L2IA-U-pl is established.
ane to the B2 unit (not the B1 unit). Then, use of the relay U-plane between the B1 unit and the B2 unit and between the BN unit and the B1 unit is terminated, and the relay U-pl between the BN unit and the B2 unit is terminated.
Only communication using ane is continued.

With this handover function, communication media can be changed without interrupting user communication.

(5) Reconnection function: When the communication between the L2IA subscribers is disconnected, the L2IA subscriber connects to the B unit by using the communication medium which the user wants to use newly or the communication medium which has been used immediately before, and communicates. L2IA identifier of the party performing the call (the destination L2IA
Identifier) is specified again, and L2IA-U-p is communicated with the destination L2IA subscriber by the dial-up connection function.
The lane is re-established. In response to the reconnection request, the destination L2IA subscriber searches for the stored reconnection information using the source L2IA identifier as a key, and resumes the connection using the data if the corresponding data exists.

The reconnection function makes it possible to resume communication from the immediately preceding communication state without depending on the medium used.

<Overall Effect> In this L2IA integrated access system, a B unit that functions as an access point of an e unit and a B unit that functions as an access point of an N unit are separately provided. By physically dividing these B units and forming a relay network by a plurality of B units, scalability can be realized.

In the L2 integrated access method, the L2
2IA subscriber uses various communication media for B
Unit, the user's data is relayed by the relay network formed by the B unit, and the L2I
The data is conveyed to the L2IA subscriber of the communication partner via the B unit connectable to the A subscriber. By freely relaying user data in the relay network formed by the B units, differences in communication media are absorbed, and by specifying an L2IA identifier that does not depend on communication media as a connection destination, it does not depend on communication media. A communication path can be established.

Further, since it is the B unit that performs transmission and reception with respect to the communication medium, the B unit can support the new communication medium by introducing a new communication interface corresponding to the new communication medium. Becomes From the perspective of L2IA subscribers, L2IA
By introducing a new communication interface corresponding to the new communication medium only in the e unit among the IA subscribers, it becomes possible to access the N unit using the new communication medium, and make any changes to the N unit No need.

Further, since the call is temporarily terminated at the B unit on the L2IA relay network side, it is possible to connect to a communication partner located on a network that cannot be directly connected by relaying through the relay network. Therefore, it is possible to freely select a connection destination network.

Further, it is possible to change the communication medium used by the user without disconnecting the communication once. Also, it is possible to make a dial-out connection from the server side to a large number of users.

Further, since the L2 integrated access method does not depend on a layer 3 protocol such as IP, an existing network environment not using IP can be used without any change. That is, assuming that Layer 2 is an end-to-end link using physical media such as ISDN or a telephone network, and Layer 3 is TCP / IP generally used in computer communication, the L2 integrated access method of the present invention uses Layer 2 and Layer 3 It can be regarded as a technology for constructing a virtual end-to-end link without depending on the physical media used for communication.
This is why this method is called L2 integrated access.
That is, according to the present invention, L2IA-C (Contro
l) -plane and L2IA-U (User) -pla
The L2IA line formed from the L2IA-nep is logically established in the U-plane of the physical communication medium, and the L2IA-Up that actually exchanges user data is used.
The lane is established by the necessary data exchange by the L2IA-C-plane.

<Signaling Operation> Next, a signaling operation for realizing the above-described overall functions of the L2IA system of the present embodiment will be described in detail.

In the following, the connection is C-pla
ne is a general term for ne and U-plane, C-plane is a connection for exchanging control information, U-plane is a connection for exchanging user data, and a relay C-plan.
e and the relay U-plane are C-pl on the L2IA relay network.
a and U-plane, L2IA-C-plane and L2IA-U-plane are C-plane and U-plane between L2IA subscribers, and L2IA line is C
It is a bundle of -plane and U-plane.

(1) Dial-up connection: Dial-up connection from the e unit to the N unit is performed as follows in accordance with the flowcharts of FIGS.

Using a communication medium desired by the user, the e unit obtains a unique terminal ID within the communication medium assigned to an appropriate B unit (Be unit) that can connect to the communication medium, and obtains the Be unit (Step 801). Here, the terminal ID is obtained from a correspondence table between the communication media provided in advance in the e unit and the terminal ID of the corresponding B unit, or by the support of the network, or the known (public) terminal ID of the Be unit. Available as

When connected, the Be unit exchanges data with the L2IA subscriber (e unit) used by the user to perform mutual authentication (step 80).
2). Here, the data used for authentication is, for example, the L2IA identifier of the e unit (source L2IA identifier) and the terminal ID of the Be unit. If authentication fails, B
The line between the e unit and the e unit is disconnected, and the operation is terminated (step 803).

If the authentication is successful in step 802, e
The unit obtains the L2IA identifier (the destination L2IA identifier) of the L2IA subscriber (N unit) of the communication partner and sends the destination L2IA identifier to the Be unit (step 804). Here, the destination L2IA identifier can be obtained from a correspondence table between each connection destination and the L2IA identifier provided in advance in the e unit.

Next, the Be unit exchanges data with the LPR to perform mutual authentication (step 805). If the authentication fails, the line between the Be unit and the e unit is disconnected, and the operation ends (step 806).

If the authentication is successful in step 805, B
The e unit sends the pair of the L2IA identifier of the source and the destination or the L2IA identifier used as a search key to the LPR.
And the highest priority RL set by the user of the currently available L2IA subscriber (N unit) with the destination L2IA identifier, called MARLD
Request D. On the other hand, the LPR searches MARLD using the destination L2IA identifier as a search key, and
Is sent to the Be unit (step 807). Where L
The PR may be determined based on the pair of the source and destination L2IA identifiers that have received the connection permission, if necessary. The Be unit is based on the acquired MARLD,
A B unit (BN unit) suitable for connecting to the L2IA subscriber (N unit) of the communication partner having the destination L2IA identifier, a communication medium used for connecting to the L2IA subscriber of the communication partner, and an L2IA of the communication partner The terminal ID of the subscriber in the communication medium can be known.

Next, the Be unit exchanges data with the BN unit indicated by MARLD to perform mutual authentication (step 808). If the authentication fails, the line between the Be unit and the e unit is disconnected, and the operation ends (step 809).

If the authentication is successful in step 808, B
The e unit establishes a relay U-plane for passing data exchanged between the Be unit and the BN unit as necessary (step 810).

Then, the Be unit sends the MARLD acquired from the LPR and the source L2IA identifier to the BN unit (step 811).

Next, the BN unit attempts to establish a connection to the N unit by performing connection using the communication medium indicated by the MARLD and transmitting to the terminal ID of the N unit indicated by the MARLD (step 812). ). This step 812 can be omitted when the N units are connected by a dedicated line. If the connection cannot be established, the BN unit notifies the Be unit of the fact, and the Be unit receiving the notification informs the LPR of the availability information of the RLD of the communication medium for which the connection has failed to be established from the “alive” state.
request to change to the "dead" state.
After receiving the notification of the completion of the RLD change from the PR, the operation returns to step 807 described above.

If a connection has been established to the N units installed in the connection destination network in step 812, the BN unit exchanges data with the N units to perform mutual authentication (step 813). Here, the data used for authentication is, for example, the L2IA identifier of the N unit (the destination L2IA identifier) and the terminal ID of the BN unit. If the authentication has failed, all connections are disconnected, and the operation is terminated (step 814).

If the authentication is successful in step 813, B
The N unit sends the source L2IA identifier to the N unit (step 815), and the N unit receives the source L2IA identifier.
It is determined whether to permit the connection based on the 2IA identifier (step 816). If the connection is not permitted, disconnect all connections and end the operation (step 817). If the connection is permitted by the N unit in step 816, the N unit notifies the BN unit of the connection permission (step 818).

[0111] The BN unit that has received the notification is a PP that is communication data of the user between the BN unit and the N unit.
An L2IA-U-plane is established between the P packet and the N unit through which the PPP related information flows, and the Be unit is notified of connection permission for the e unit (step 81).
9).

[0112] The Be unit that has received this notification exchanges the user's PPP packet and P between the Be unit and the BN unit.
A relay U-plane through which PP related information flows is established, and connection permission is notified to the e unit (step 820). Then, the Be unit establishes an L2IA-U-plane between the Be unit and the e unit through which the PPP packet of the user and the PPP-related information flow (step 821). As a result, a communication path through which the user's PPP packet and PPP-related information flows is established between the e unit and the N unit, and communication between the e unit and the N unit is started (step 822).

As described above, the user can freely connect to a desired network by connecting to an appropriate B unit using the communication medium desired by the user and specifying the L2IA identifier of the partner to be connected.

(2) Dial-out connection: Dial-out connection from the N unit to the e unit is performed as follows in accordance with the flowcharts of FIGS.

The N unit installed in the user's home network is the terminal ID assigned to the BN unit.
And attempts to establish a connection to the BN unit (step 901). Here, the terminal ID can be obtained from a correspondence table between the communication media provided in advance in the N units and the terminal ID of the corresponding B unit, or as a well-known (disclosed) terminal ID of the BN unit.

Then, if necessary, the N unit is BN
Data is exchanged with the unit to perform mutual authentication (step 902). Here, the data used for authentication is, for example, the L2IA identifier of the N unit (source L2IA identifier).
And the terminal ID of the BN unit. If the authentication fails, the line between the BN unit and the N unit is disconnected, and the operation ends (step 903).

If the authentication is successful in step 902, N
The unit obtains the L2IA identifier (destination L2IA identifier) of the communication partner L2IA subscriber (e unit) and sends the destination L2IA identifier to the BN unit (step 904). Here, the destination L2IA identifier can be obtained from a correspondence table between each connection destination and the L2IA identifier provided in advance in the N unit.

Next, the BN unit exchanges data with the LPR to perform mutual authentication (step 905). If the authentication fails, the line between the BN unit and the N unit is disconnected, and the operation ends (step 906).

If authentication is successful in step 905, B
The N unit sends a pair of the L2IA identifier of the source and the destination or the L2IA identifier used as a search key to the LPR.
And requests the highest priority RLD called MARLD, which is set by the user of the currently available e-unit with the destination L2IA identifier. In contrast,
LPR uses the destination L2IA identifier as a search key and MAR
The LD is searched and MARLD is sent to the BN unit (step 907). Here, the LPR may be determined based on the pair of the L2IA identifier of the source and the destination, which have received the connection permission, as necessary.

Next, the BN unit exchanges data with the Be unit indicated by MARLD to perform mutual authentication (step 908). If the authentication fails, the connection between the BN unit and the N unit is disconnected, and the operation ends (step 909).

If the authentication is successful in step 908, B
The N unit establishes a relay U-plane between the BN unit and the Be unit as necessary (step 91).
0).

The BN unit sends the MARLD acquired from the LPR and the source L2IA identifier to the Be unit (step 911).

Next, the Be unit attempts to establish a connection to the e unit by performing connection using the communication medium indicated by the MARLD and transmission toward the terminal ID of the e unit indicated by the MARLD (step 912). ). If the connection cannot be established, the Be unit notifies the BN unit of this (step 913), and the BN unit receiving the notification notifies the BN unit of the LP.
R requests the RLD to change the RLD of the communication medium for which connection establishment failed among the RLDs related to the destination L2IA identifier, and requests the RLD with the next highest priority (step 914). On the other hand, the LPR changes the RLD availability information of the communication medium to the “dead” state or the “unknown” state and changes the RLD to which the user has set the next highest priority at that time to the BN.
Send to the unit (step 915).

If the connection is established up to the e unit in step 912, the Be unit exchanges data with the e unit to perform mutual authentication (step 91).
6). If the authentication fails, all connections are disconnected, and the operation is terminated (step 917).

If the authentication is successful in step 916, B
The e unit sends the source L2IA identifier to the e unit (step 918), and the e unit sends the received source L2IA identifier.
It is determined whether to permit the connection based on the 2IA identifier (step 919). If the connection is not permitted, disconnect all connections and end the operation (step 920).

When the connection is permitted by the e unit in step 919, the Be unit establishes an L2IA-U-plane, which is a communication path through which the user's PPP packet and the PPP-related information flow, between the Be unit and the e unit.
The BN unit is notified of connection permission for the N unit (step 921).

[0127] The BN unit that has received the notification transmits the user's PPP packet and the P packet between the BN unit and the Be unit.
A relay U-plane through which PP related information flows is established (step 922). Then, the BN unit notifies the N unit of the connection permission, and establishes an L2IA-U-plane between the BN unit and the N unit through which the user packet and the related information flow (step 923). As a result, the user's PPP packet and PP
A communication path through which the P-related information flows is established between the N unit and the e unit, and communication between the N unit and the e unit is started (step 924).

As described above, regardless of where the user of the e unit moves and which communication medium can be used to connect to the e unit, the e unit held by the moving user is transferred from the server (N unit) side. Dial-out connection can be performed, and communication using communication media reflecting the intention of the user of the e unit can be realized.

(3) Handover: Handover for changing the communication medium used by the e unit during communication between the N unit and the e unit can be realized by two procedures.

(3.1) The first procedure (scenario I) is performed as follows according to the flowchart of FIG.

The e unit changes the communication medium to be used (handover) to the currently connected B unit (B1).
Unit) (step 1001).

Then, similarly to the dial-up connection procedure described above, using the communication medium desired by the user,
The e unit obtains the terminal ID assigned to another B unit (B2 unit) and connects to the B2 unit (step 1002).

Next, the e unit exchanges data with the B2 unit to perform mutual authentication (step 100).
3). If the authentication fails, the connection between the e unit and the B2 unit is disconnected, and the operation ends (step 1004).

If the authentication is successful in step 1003,
The e unit obtains the L2IA identifier (destination L2IA identifier) of the connected N unit, and sends the destination L2IA identifier to the B2 unit (step 1005). here,
The destination L2IA identifier can be obtained from a correspondence table provided in the e unit.

Next, the B2 unit exchanges data with the LPR to perform mutual authentication (step 1006). If the authentication fails, the connection between the e unit and the B2 unit is disconnected, and the operation is terminated (step 10).
07).

If the authentication is successful in step 1006,
The B2 unit sends a pair of a source and destination L2IA identifier or an L2IA identifier used as a search key to the LP.
R, requesting the currently available and highest priority RLD, called MARLD. On the other hand, the LPR searches for MARLD using the destination L2IA identifier as a search key, and sends MARLD to the B2 unit (step 10).
08). The B2 unit can know the BN unit based on the acquired MARLD.

Next, the B2 unit exchanges data with the BN unit indicated by MARLD to perform mutual authentication (step 1009). If the authentication fails, the connection between the e unit and the B2 unit is disconnected, and the operation ends (step 1010).

If the authentication is successful in step 1009,
The B2 unit establishes a relay U-plane for transmitting user data between the B2 unit and the BN unit (step 1011). Also, the B2 unit establishes an L2IA-U-plane between the B2 unit and the e unit that flows user data between the e unit (step 101).
2).

The unit e changes the flow of user data from the connection via the B1 unit to the connection via the B2 unit, and starts communication via the B2 unit (step 1013).

Next, the communication path between the BN unit and the B1 unit and the communication path between the B1 unit and the e unit are disconnected (step 1014).

(3.2) On the other hand, the second procedure (scenario I)
I) is performed as follows according to the flowcharts of FIGS.

The e unit changes the communication medium to be used (handover) to the currently connected B unit (B1).
Unit) (step 1101).

Next, the B1 unit sends a pair of an L2IA identifier of a source and a destination or an L2IA identifier used as a search key to the LPR, and uses the source L2IA identifier as a key, which is called MARLD, which is currently available and has a priority. Request highest RLD (step 110)
2). On the other hand, the LPR searches for the MARLD using the source L2IA identifier as a search key, and sends the MARLD to the B1 unit (step 1103).

Next, the B1 unit exchanges data with the B2 unit indicated by MARLD to perform mutual authentication (step 1104). If the authentication fails, the connection between the B1 unit and the B2 unit is disconnected, and the operation ends (step 1105).

Next, the B1 unit stores the handover data HD (step 1106). Here, the handover data includes a handover ID for identifying each handover and an L2IA relay ID of the B1 unit.
And a pair of a source and destination L2IA identifier, and "going" information indicating that handover is being performed. This handover data is used to specify the L2IA-U-plane to be handed over. The L2IA relay ID of the B1 unit indicates that the L2IA-U-plane to be subjected to the handover is the L2IA-U-plane set through the B1 unit.

Next, the B1 unit transmits the MARLD, the source L2IA identifier, and the handover data HD to the B2.
It is sent to the unit (step 1107). The B2 unit that has received the transmission request attempts to establish a connection between the e unit and the B2 unit by performing connection using the communication medium indicated by the received MARLD and transmitting to the terminal ID of the e unit ( Step 110
8).

If the connection establishment fails at step 1108, the B2 unit notifies the B1 unit of the connection establishment failure (step 1109).
The unit requests the LPR to change the RLD of the communication medium for which connection establishment has failed to the "dead" state, and requests the RLD that is currently available and has the next highest priority set by the user (step 1110). Then, the operation returns to step 1103.

If the connection is established in step 1108, the B2 unit exchanges data with the e unit to perform mutual authentication (step 1111). If the authentication fails, the connection between the e unit and the B2 unit is disconnected, and the operation is terminated (step 111).
2). Here, the data used for the authentication is, for example, the terminal ID of the B2 unit and the L2IA identifier of the e unit.

If the authentication is successful in step 1111,
The B2 unit uses the communication medium used in step 1108 to transmit an L2IA-U-plane between the B2 unit and the e unit through which user data flows between the e units.
Is established (step 1113). The B2 unit is an L2IA-U-pl between the e unit and the B2 unit.
is notified to the B1 unit (step 11).
14).

Next, the B1 unit is a relay U-pla through which user data flows between the B1 unit and the B2 unit.
ne that the user data previously sent to the e unit is now sent to the B2 unit instead.
Two units are notified, and transmission of user data is started (step 1115). The B2 unit that has received the notification notifies the e unit that the user data is to be transmitted, and starts data transmission (step 1116).

Next, the B1 unit notifies the BN unit of the handover data HD and the L2IA relay ID of the B2 unit (step 1117). On the other hand, BN
The unit exchanges data with the B2 unit to perform mutual authentication, and checks handover target user data for performing a handover based on the L2IA identifier pair in the handover data HD (step 1118). If the authentication fails, the BN unit notifies the B1 unit of the failure, disconnects the connection established for the handover, and ends the operation (step 111).
9).

If the authentication is successful in step 1118,
The BN unit establishes a relay U-plane through which the user data indicated by the L2IA identifier pair in the handover data HD flows between the B2 unit and the BN unit,
Notifying the B1 unit of stopping transmission of user data to the B1 unit, and notifying the B2 unit of start of transmission of user data to the B2 unit,
Transmission of user data to the two units is started (step 1120).

The B1 unit that has received the notification disconnects the connection between the B1 unit and the e unit, the B2 unit, and the BN unit, and deletes the stored handover data HD (step 1121).

Then, communication from the e unit to the N unit via the B2 unit and the BN unit is started (step 1122).

According to any of the above procedures, communication media can be automatically changed in accordance with the user's request in response to a media change request from the user.

When the user directly requests the B unit to add an RLD related to a new communication medium or change the priority between communication media, the B unit receiving the request can request the LPR to change the RLD. The RLD managed by the LPR can always reflect the user's intention. Moreover, in the LPR, since the RLD specifies the B unit, the user can always use an appropriate B unit.

(4) Reconnection: After the communication medium used for the communication becomes unusable or after the communication is interrupted by a request from the user, the user terminal makes a call and resumes the communication. Is performed as follows according to the flowchart of FIG.

The communication medium used was disconnected.
Alternatively, the Be unit that has received the request for interruption from the user's e unit during communication notifies the BN unit of the interruption of communication and the L2IA identifier of the e unit (step 1).
201).

The BN unit having received the notification notifies the N unit of the interruption of the communication and the L2IA identifier of the e unit, and interrupts the communication between the BN unit and the N unit (step 1202).

The N unit that has received the notification saves the current communication state using the L2IA identifier of the connection destination e unit as a key (step 1203). Here, the period for storing this data can be determined in advance. The storage period of the user data to which the PPP interface is statically assigned may be set by the user himself. I
In the case of a dynamic connection in which a network protocol identifier such as a P-address is given for each connection, this data is stored only for a limited period.

After the communication is interrupted, the e-unit, based on the dial-up connection procedure described above, re-connects using the communication medium desired by the user, and the L2IA-U-U-L-U-U-user data flows between the e unit and the N unit. p
When the connection is re-established (step 1204), the N unit searches for the stored data using the L2IA identifier of the connected e unit. The communication is resumed from the communication state immediately before the interruption (step 12).
05).

Thus, when the user resumes communication,
Communication can be resumed from the communication state immediately before the interruption. Since the stored data is selected based on the L2IA identifier of the connection destination, not only when the PPP interface is statically allocated but also when the connection is dynamic, without depending on the communication medium used, Communication can be resumed from the state immediately before.

Note that a call from the network side can be realized by the same procedure as that for a call from the terminal described above. In that case, the communication state of the user is L2 of the e unit.
It is stored using the IA identifier as a key. Then, based on the dial-out connection procedure described above, L2IA-U-pla through which user data flows between the e unit and the N unit.
Ne is established, and communication can be resumed by calling the stored data using the L2IA identifier of the connection destination e unit as a key.

In the above description, when the optional availability information is omitted or ignored in the RLD, the above-described signaling operation simply requests the RPR of the highest priority RLD without referring to the availability information. It may be modified as follows.

In the above-described signaling operation, authentication is performed to check whether the communication partner is a correct communication partner and to prevent theft or falsification of data by a malicious third party. Authentication fails when the communication partner is not the correct communication partner authorized to exchange data.

It is also possible to perform communication between different e units via N units of the L2 integrated access system of the present invention.

The present invention is not limited to the above-described embodiment, but can be variously modified without departing from the gist thereof.

[0168]

As described above, according to the present invention, P
A communication line for transmitting a PP packet and PPP-related information,
It is possible to provide a data link (layer 2) integrated access method capable of providing multi-function access to a computer network by providing the data link independent of a physical line.

[Brief description of the drawings]

FIG. 1 is a schematic block diagram showing an overall configuration of an L2 integrated access system according to an embodiment of the present invention.

FIG. 2 is a block diagram illustrating an example of an internal configuration of an e unit in the L2 integrated access system of FIG.

FIG. 3 is a block diagram showing another example of the internal configuration of the e unit in the L2 integrated access system of FIG. 1;

FIG. 4 is a block diagram illustrating an example of an internal configuration of an N unit in the L2 integrated access system of FIG. 1;

FIG. 5 is an LP in the L2 integrated access system of FIG. 1;
3 is a block illustrating an example of a format of an RLD registered in R.

FIG. 6 is an LP in the L2 integrated access system of FIG. 1;
3 is a block diagram illustrating an example of an internal configuration of R.

FIG. 7 is a block diagram illustrating an example of an internal configuration of a B unit in the L2 integrated access system of FIG. 1;

FIG. 8 is a flowchart showing a first half of an example of a signaling operation for realizing a dial-up connection in the L2 integrated access system of FIG. 1;

9 is a flowchart illustrating a second half of an example of a signaling operation for realizing a dial-up connection in the L2 integrated access system of FIG. 1;

FIG. 10 is a flowchart showing a first half of an example of a signaling operation for realizing a dial-out connection in the L2 integrated access system of FIG. 1;

FIG. 11 is a flowchart illustrating a second half of an example of a signaling operation for realizing a dial-out connection in the L2 integrated access system of FIG. 1;

FIG. 12 is a flowchart showing an example of a signaling operation for realizing a handover (scenario I) in the L2 integrated access system of FIG. 1;

13 is a flowchart showing a first half of an example of a signaling operation for realizing a handover (scenario II) in the L2 integrated access system of FIG. 1;

14 is a flowchart illustrating a second half of an example of a signaling operation for realizing a handover (scenario II) in the L2 integrated access system of FIG. 1;

FIG. 15 is a flowchart illustrating an example of a signaling operation for realizing reconnection in the L2 integrated access system of FIG. 1;

[Explanation of symbols]

 10 e unit 20 N unit 100 L2IA relay network 110 B unit 120 LPR 200 Communication media

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Satoshi Ono 3-19-2 Nishi-Shinjuku, Shinjuku-ku, Tokyo Nippon Telegraph and Telephone Corporation (72) Inventor Kazuyuki Terao 3--19, Nishishinjuku, Shinjuku-ku, Tokyo 2 Nippon Telegraph and Telephone Corporation (72) Inventor Susumu Miyagawa United States 19805 Wilmington, Delaware Newcastle County Center Road 1013 Corporation Service Company (56) References JP-A-6-104926 (JP, A) JP-A-7-170286 (JP, A) JP-A-10-91551 (JP, A) JP-A-11-88438 (JP, A) JP-A-11-298527 (JP, A) Table 9-505951 (JP, A) WO 97/33444 (WO, A1) US Pat. No. 5,664,007 (US, A) US Pat. No. 5,918,019 (US, A) Electronic information communication IEICE Technical Report, IN 97-65, July 18, 1997 (58) Fields investigated (Int. Cl. ⁷ , DB name) H04L 12/56 H04L 12/66 H04L 12/46 H04L 12/28 H04M 3 / 00 H04M 11/00 H04Q 7/38

Claims (15)

(57) [Claims] An L2IA (Layer 2 integrated access) subscriber supporting communication between user terminals using various communication media, wherein each L2IA subscriber uniquely identifies each L2IA subscriber in a system. A terminal ID for uniquely identifying each L2IA subscriber in each communication medium associated with each L2IA subscriber; a plurality of relay units and at least one LPR (Locati
on and Preference Register), wherein the relay unit is connected to an L2IA subscriber via various communication media, and relays communication between the L2IA subscribers via the L2IA relay network. Is provided corresponding to one communication medium, and an L2IA relay ID for uniquely identifying each relay unit in the L2IA relay network and a relay unit for uniquely identifying each relay unit in each communication medium associated with each relay unit. The LPR indicates the terminal ID of the L2IA subscriber and the L2IA relay ID of the relay unit in association with the L2IA identifier of each L2IA subscriber for each potentially available communication medium. Registered Location Data)
The relay unit determines the L2I based on the registered RLD in association with the L2IA identifier of the L2IA subscriber.
An L2 integrated access system, comprising: a device for relaying communication between A subscribers. 2. The L2IA subscriber is an e-type L2 having at least one communication interface, one PPP interface and one L2IA interface.
An IA subscriber, at least one communication interface, at least one PPP interface,
It includes an N-type L2IA subscriber having one L2IA interface, each communication interface can set up a connection with a relay unit, and each PPP (Point-
2. The interface according to claim 1, wherein the interface is capable of exchanging a PPP packet and PPP-related information with a user terminal, and each L2IA interface is capable of selectively interfacing a communication interface and a PPP interface. L2 integrated access system. 3. An L2IA-U, which is a logical connection through which user communication data flows, to one or more other L2IA subscribers.
The L2 integrated access system according to claim 1, further comprising a function of establishing one or more planes. 4. Each relay unit has a function of transmitting / receiving a signaling message to / from the LPR with another relay unit in the L2IA relay network and a logical connection supporting L2 integrated access from the L2IA subscriber to the relay unit. The L2 integrated access system according to claim 1, further comprising a function of establishing a certain L2IA channel for an L2IA subscriber. 5. The RLD registered in the LPR may indicate a priority of each potentially available communication medium set by a user and optionally a current availability of each potentially available communication medium. The L2 integrated access system according to claim 1, further comprising: 6. An L2IA subscriber provided at a certain user terminal associated with a certain communication medium establishes a dial-up connection to another L2IA subscriber provided at a user's home network associated with another communication medium. By setting a connection to a certain relay unit provided corresponding to the certain communication medium suitable for the L2IA subscriber and specifying the L2IA identifier of the other L2IA subscriber for the certain relay unit, Based on a certain RLD registered by the LPR in association with the L2IA identifier of another L2IA subscriber, the certain relay unit may be provided with another relay provided corresponding to the other communication medium suitable for the other L2IA subscriber. Set up a connection to the unit and The L according to claim 1, wherein the other relay unit sets a connection to the other L2IA subscriber based on the LD.
2 Integrated access system. 7. An L2IA subscriber provided in a user's home network associated with a certain communication medium establishes a dial-out connection to another L2IA subscriber provided in a user terminal associated with another communication medium. By setting a connection to a certain relay unit provided corresponding to the certain communication medium suitable for a certain L2IA subscriber and specifying the L2IA identifier of the other L2IA subscriber for the certain relay unit, Based on a certain RLD registered by the LPR in association with the L2IA identifier of the other L2IA subscriber, the certain relay unit is provided in correspondence with the other communication medium suitable for the other L2IA subscriber. Set up a connection to the relay unit, The L according to claim 1, wherein the other relay unit sets a connection to the other L2IA subscriber based on the LD.
2 Integrated access system. 8. An L2IA subscriber provided in a user terminal, which is communicating with another L2IA subscriber provided in a user's home network, is connected to another L2IA subscriber.
2) A handover for changing a communication medium used for communication with an IA subscriber from a first communication medium to a second communication medium is performed by handover to a first relay unit provided corresponding to the first communication medium. And a connection to a second relay unit provided corresponding to the second communication medium suitable for the certain L2IA subscriber is set, and the other L2IA subscriber is set for the second relay unit. By specifying the L2IA identifier of the second L2IA subscriber, the second relay unit based on a certain RLD registered by the LPR in association with the L2IA identifier of the other L2IA subscriber, The third relay unit provided corresponding to the communication media attached to the home network And the first relay unit disconnects the connection between the certain L2IA subscriber and the first relay unit and the connection between the first relay unit and the third relay unit. The L2 integrated access system according to claim 1, wherein: 9. An L2IA subscriber provided in a user terminal, which is communicating with another L2IA subscriber provided in a user's home network, is connected to another L2IA subscriber provided in the user terminal.
2) A handover for changing a communication medium used for communication with an IA subscriber from a first communication medium to a second communication medium is performed by handover to a first relay unit provided corresponding to the first communication medium. Request, the first relay unit obtains a certain RLD registered by LPR in association with the L2IA identifier of the certain L2IA subscriber, and obtains the second communication medium suitable for the certain L2IA subscriber. Requesting and setting a connection to the certain L2IA subscriber to a second relay unit indicated by the certain RLD, the first relay unit being connected to the second relay unit. And the communication data is transmitted from the first relay unit to the certain L2IA.
A third relay unit provided to correspond to a communication medium associated with a home network of a user suitable for the other L2IA subscriber, wherein the third relay unit is caused to flow to the subscriber via the second relay unit. Notifying the relay unit of the second relay unit, the third relay unit establishes a connection between the third relay unit and the second relay unit, and communicates data to the second relay unit. And stops transmission of communication data to the first relay unit, and the first relay unit establishes a connection between the certain L2IA subscriber and the first relay unit and the first relay unit. The connection between the unit and the second relay unit and the connection between the first relay unit and the third relay unit are disconnected. L according to claim 1, wherein the
2 Integrated access system. 10. An L2IA subscriber provided in a user's home network stores a communication state of communication with another L2IA subscriber when another L2IA subscriber provided in a user terminal interrupts communication, The other L2IA subscriber is the L2
2. The L2 integrated access system according to claim 1, wherein when reconnecting to the IA subscriber, communication with the other L2IA subscriber is restarted from the stored communication state. 11. The integrated L2 access system according to claim 1, wherein an L2IA subscriber provided at a certain user terminal associated with a certain communication medium is provided on a home network of a user associated with another communication medium. (A) setting a connection from the certain L2IA subscriber to a certain relay unit provided corresponding to the certain communication medium suitable for the certain L2IA subscriber; (B) specifying the L2IA identifier of the other L2IA subscriber from the certain L2IA subscriber to the certain relay unit; and (c) specifying the L2IA identifier of the other L2IA subscriber specified in step (b). LPR Setting a connection from the certain relay unit to another relay unit provided for the other communication medium suitable for the other L2IA subscriber, based on the certain RLD registered by (d). Setting a connection from the other relay unit to the other L2IA subscriber based on the certain RLD. 12. The L2 integrated access system according to claim 1, wherein an L2IA subscriber provided in a home network of a user associated with a certain communication medium is provided at a certain user terminal associated with another communication medium. (A) setting up a connection from the certain L2IA subscriber to a certain relay unit provided for the certain communication medium suitable for the certain L2IA subscriber; (B) specifying the L2IA identifier of the other L2IA subscriber from the certain L2IA subscriber to the certain relay unit; and (c) the L2IA identifier of the other L2IA subscriber specified in step (b). LPR Requesting a connection from the certain relay unit to another relay unit provided for the other communication medium suitable for the other L2IA subscriber based on the certain RLD registered by the first relay unit (D) the certain RL
D from the other relay unit to the other L2IA
Setting up a connection to the subscriber. 13. The L2 integrated access system according to claim 1, wherein the L2IA subscriber provided in the user terminal is communicating with another L2IA subscriber provided in the user's home network. (A) changing the communication medium used for the communication of the first communication medium from the first communication medium to the second communication medium;
Requesting a handover from an IA subscriber to a first relay unit provided corresponding to the first communication medium; and (b) the second L2IA subscriber being suitable for the certain L2IA subscriber from the second L2IA subscriber. Setting a connection to a second relay unit provided corresponding to the communication medium; and (c) designating the L2IA identifier of the other L2IA subscriber from the certain L2IA subscriber to the second relay unit And (d) the second L2IA from the second relay unit based on a certain RLD registered by LPR in association with the L2IA identifier of the other L2IA subscriber specified in the step (c). Communication media associated with the user's home network suitable for the subscriber And setting a connection to a third relay unit provided in correspondence with, (e)
A handover method, comprising a step of disconnecting a connection between the certain L2IA subscriber and the first relay unit and a connection between the first relay unit and the third relay unit. 14. The L2 integrated access system according to claim 1, wherein one L2IA subscriber provided in the user terminal is communicating with another L2IA subscriber provided in the user's home network. (A) changing the communication medium used for the communication of the first communication medium from the first communication medium to the second communication medium;
Requesting a handover from an IA subscriber to a first relay unit provided corresponding to the first communication medium; and (b) responding to the L2IA identifier of the certain L2IA subscriber in the first relay unit. And obtaining a certain RLD registered by the LPR, and (c) from a second relay unit provided corresponding to the second communication medium suitable for the certain L2IA subscriber and indicated by the certain RLD. Setting a connection to the certain L2IA subscriber; and (d) setting a connection from the first relay unit to the second relay unit so that communication data is transmitted from the first relay unit to the certain L2IA subscriber. Flowing through the second relay unit; (e) It said other L from the first relay unit
Notifying the second relay unit to a third relay unit provided for the 2IA subscriber and corresponding to the communication medium associated with the user's home network; and (f) notifying the third relay unit of the second relay unit from the third relay unit. Setting a connection between the third relay unit and the second relay unit to start transmission of communication data to the second relay unit and stopping transmission of communication data to the first relay unit (G) a connection between the certain L2IA subscriber and the first relay unit;
A handover method comprising a step of disconnecting a connection between the first relay unit and the second relay unit and a step of disconnecting a connection between the first relay unit and the third relay unit. 15. The reconnection method in the L2 integrated access system according to claim 1, wherein (a) one L2IA subscriber provided in a user's home network communicates with another L2IA subscriber provided in a user terminal. Storing the communication state of communication with the other L2IA subscriber when the communication is interrupted;
(B) the other L2IA subscriber is the L2IA
Re-establishing communication between the certain L2IA subscriber and the other L2IA subscriber from the communication state stored in the step (a) when re-connection to the subscriber is performed. .